A light emitting diode (LED) is a semiconductor device that transmits and receives signals by converting electrical signals into infrared light or visible light using properties of compound semiconductors and is widely used as a light source.
Group III-V nitride semiconductor materials are recently receiving attention as main materials of light emitting devices such as LEDs and laser diodes (LDs) due to physical and chemical properties thereof.
Such LEDs are eco-friendly, since hazardous substances, such as mercury (Hg) used in conventional lighting apparatuses such as incandescent lamps and fluorescent lamps, are not used therein, and have long lifespan and low power consumption. Thus, LEDs are replacing conventional light sources.
FIG. 1 is a cross-sectional view illustrating a conventional light emitting device package.
The light emitting device package illustrated in FIG. 1 consists of package bodies 10A and 10B electrically separated from each other by an insulating material 20, a light emitting device 30, a submount 40, wires 50A and 50B, and a molding member 60.
When the light emitting device 30 of FIG. 1 emits deep ultraviolet (DUV) light, the molding member 60 has a very low viscosity. For example, when the light emitting device 30 emits blue light, the molding member 60 has a viscosity greater than 20 Pa·sec. When the light emitting device 30 emits DUV light, the molding member 60 has a very low viscosity of 3.2 Pa·sec. Accordingly, the molding member 60 may be formed in a flat dome shape, resulting in decreased light extraction efficiency.
In addition, due to differences in thermal expansion coefficient between the submount 40 and the package bodies 10A and 10B formed of aluminum (Al), contact properties therebetween may be deteriorated, thereby reducing product reliability.
In addition, low reliability of bonding between the package bodies 10A and 10B formed of aluminum (Al) and the wires 50A and 50B formed of gold (Au) may cause product defects.